Add ImeMenuTray element.

ash/common/system/chromeos/ime_menu/ime_menu_tray.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef ASH_COMMON_SYSTEM_CHROMEOS_IME_MENU_IME_MENU_TRAY_H_
+#define ASH_COMMON_SYSTEM_CHROMEOS_IME_MENU_IME_MENU_TRAY_H_
+
+#include "ash/ash_export.h"
+#include "ash/common/system/ime/ime_observer.h"
+#include "ash/common/system/tray/system_tray_delegate.h"
+#include "ash/common/system/tray/tray_background_view.h"
+#include "base/macros.h"
+
+namespace views {
+class Label;
+}  // namespace views
+
+namespace ash {
+class StatusAreaWidget;
+class WmWindow;
+
+class ASH_EXPORT ImeMenuTray : public TrayBackgroundView, public IMEObserver {

[James Cook, 2016/07/12 17:53:37]

nit: class comment please.

[Azure Wei, 2016/07/14 02:57:02]

Done.

+ public:
+  explicit ImeMenuTray(WmShelf* wm_shelf);
+  ~ImeMenuTray() override;
+
+  // TrayBackgroundView:
+  void SetShelfAlignment(ShelfAlignment alignment) override;
+  base::string16 GetAccessibleNameForTray() override;
+  void HideBubbleWithView(const views::TrayBubbleView* bubble_view) override;
+  void ClickedOutsideBubble() override;
+  bool PerformAction(const ui::Event& event) override;
+
+  // IMEObserver:
+  void OnIMERefresh() override;
+  void OnIMEMenuActivationChanged(bool is_activated) override;
+
+ private:
+  // To allow the test class to access |label_|.
+  friend class ImeMenuTrayTest;
+
+  // Updates the text of the label on the tray.
+  void UpdateTrayLabel();
+
+  // Sets the border of the label to keep the tray width consistant.
+  void SetLabelBorder();
+
+  views::Label* label_;
+  IMEInfo current_ime_;
+  bool is_active_;

[James Cook, 2016/07/12 17:53:37]

nit: Document what is active. The button (highlighted?). The menu (shown?).
Both?

[Azure Wei, 2016/07/14 02:57:02]

Replaced this with function SetTrayActivation(bool is_active_);

+
+  DISALLOW_COPY_AND_ASSIGN(ImeMenuTray);
+};
+
+}  // namespace ash
+
+#endif  // ASH_COMMON_SYSTEM_CHROMEOS_IME_MENU_IME_MENU_TRAY_H_